Shami Chakrabarti is to Britain’s intelligentsia what Posh Spice was to teenage girls. Well, if success and celebrity are synonymous. Always available to perform on the Today programme or in the columns of serious newspapers, the director of Liberty has made herself the closest thing this country possesses to an intellectual pin-up girl. But in making her instant opinions so universally available she has done little for the cause she claims to promote.

The core challenge to democracy since September 11, 2001, has been to achieve proportionality between the competing priorities of individual liberty and public protection. Ms Chakrabarti has come down relentlessly on the quasi-anarchist side of the debate. Her defence of individual rights against collective needs takes the demos out of democracy and leaves her organisation marooned on the extra-parliamentary left of politics.

In her enthusiasm to see the good in every terrorist suspect and a heart of unalloyed evil in each successive Home Secretary, the lady from Liberty has revealed extraordinary naivety about Labour’s favourite tactic. Acquired from Bill Clinton, the trick known as triangulation seeks to popularise government policy by contrasting it with the views of unpopular minorities. Ms Chakrabarti never rejects the invitation to play the extremist.

Almost single-handedly she has shifted the civil liberties lobby so far beyond the parameters of mainstream opinion that ministers pray she will oppose them. Their logic is simple: if Liberty objects, Middle Britain will automatically conclude that a policy is pure common sense.

Ms Chakrabarti easily achieved her ambition to reassert Liberty’s prominence after its name change from the National Council for Civil Liberties. But since then, through reams of anti-terror law and attempts to control asylum and antisocial behaviour, she has forgotten what the “civil” in that historic title meant. Liberty’s guiding principle should be John Stuart Mill’s advice that “The liberty of the individual must be thus far limited; he must not make himself a nuisance to other people.” By championing the errant individual to the detriment of the majority she ignores it completely.

Few mistakes better illustrate this debilitating flaw than Liberty’s backing for Graeme Chessum, the Nottinghamshire man banned from his local pubs for behaving aggressively towards staff at one of them. The Pubwatch scheme under which he is excluded is a fine example of community action against antisocial conduct. As such it achieves the utilitarian ideal of the greatest good of the greatest number. By threatening to challenge it under human rights legislation Liberty extends beyond absurdity its director’s faith that high profile is preferable to high principle.